1. Field of the Invention
In many situations, it is desirable to determine the amount of a specific receptor which may be present in a physiological fluid. For many physiological compounds, there are specific receptors which will bind. For example, thyroxine is specifically bound by thyroxine binding globulin and thyroxine binding prealbumin. Certain steriods also have specific naturally occuring receptors. There is, therefore, an interest in being able to determine these receptors.
There is the further situation that for a wide variety of drugs and naturally occuring physiologically effective materials, methods of determination have been evolved which require the use of antibodies. With haptens, for example, the hapten is conjugated to an antigen and then injected into an animal. After harvesting of the antibodies, it is necessary to be able to determine the antibody titer and binding constant. For this purpose, it is necessary to have an accurate sensitive method to measure the amount of antibody which is specific for the hapten or antigen of interest.
Finally, for certain diseases e.p. syphilis, one can determine the presence of the microorganism by assaying for antibodies to the microorganism. It is found in these instances that there can be simple compounds which will bind specifically to the antibodies to the organism. This technique then affords a method for determining the antibodies to the organism in the physiological fluid.
2. Description of the Prior Art
U.S. Pat. No. 3,935,074 describes a technique for determining ligands employing steric hindrance between antibodies. See also the reference cited therein. See also Abstracts of a Symposium-Enzymes General V, Items 2028 and 2029, Carrico, et al (1976); Carrico, et al Anal. Biochem. 72 271 (1976); and Schroeder, et al, ibid 72 7283 (1976).